Floating dock lift

ABSTRACT

A docking type system for lifting boats out of the water for storage and servicing by the provision of a lifting system which elevates both the vessel and the dock above the surface of a body of water. The docking system comprises a plurality of fixed piles, a platform floating between the piles, an upper surface above the body of water and a frame that is capable of supporting the vessel. The platform is located and supported between the piles and is capable of being raised above, and lowered below, the surface of the body of water. The frame and the platform are relatively disposed such that when the frame lifts a vessel above the surface of the body of water it also lifts the platform above the surface of the body of water.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to improvements in boat lifts for elevating boatsout of the water when not in use for storage and servicing. Moreparticularly, it concerns a boat lift of the cradle type that isassociated with some form of permanent berth.

The docking system of the present invention is a solution for owners ofwater front residences who wish to keep a boat at a floating docklocated at their seaside frontage but have difficulty because the seastate is sometimes too rough to permanently leave a boat in the waterattached to a floating dock.

The term boat is herein used in its broad generic sense and includes allsports and recreational vessels and watercraft, powered by engine orsail or un-powered, in general use.

2. Description of the Prior Art

Boat lifts are well known in the art for raising watercraft out of thewater to protect it from the effects of continued immersion. It is wellknown that continued exposure to the water ultimately deteriorates thehull of such vessels. salt water is particularly damaging, but evenfresh water storage results in the formation of algae and otherdeleterious matter on the hull. The ideal maintenance procedure is tocompletely remove the boat from the water and wash down'the hull afterevery use of the boat and to store it fully out of the water betweenuses, for example, in a boat shed. It is also advantageous to remove theboat from the water to protect it from damage in adverse weatherconditions.

However removing a boat from the water between uses and storing it onland is not convenient or even possible for many recreational boatowners. Owners of water front residences also may wish to have theirboat constantly ready to use and choose to leave their boat permanentlymoored near their residence. Consequently the boat spends the majorityof its life merely sitting in the water and constantly deterioratingfrom the mechanical action of wind, waves, tides and moorings, thechemical action of water, salts and pollutants and the action of marineorganisms.

In these situations an alternative either to land storage or to mooringand storing a boat in the water tied to a pier or bulkhead is the boatlift. This is a device for lifting the boat clear of the water at theplace where the boat is moored. A large variety of different types ofboat lifts have been developed to handle various kinds of boats indifferent ways and locations. In a broad sense, these may be dividedinto mobile lifts that can lift and move boats about on land or waterand permanent lifts designed to lift boats at a fixed location. Thepresent invention concerns a fixed position boat lift.

In the simplest form of permanent location type boat lift, the boat liftmechanism is mounted directly on the bed of the body of water, generallyby means of piers, and a mechanical device, generally a cable winchingsystem, is used to raise or lower the boat. The cables may be attacheddirectly to some portion of the superstructure of the boat, but moretypically the cables are connected to a lift cradle that engages of thehull of the boat from its underside. The cradle may be either hoistedvertically or pulled along an inclined ramp or track in and out of thewater by cables that are attached to supports positioned above thewater. The present invention relates to a vertical hoist cradle boatlift.

Prior art cable hoist cradle boat lifts which may be suitable for usewith recreational boats are illustrated by U.S. Pat. No. 4,686,920(Thomas) which discloses a boat lift having a motorized cable winchsystem attached to fixed piers, U.S. Pat. No. 4,329,082 (Gillis) whichdiscloses a motorized system fixed to a dock and U.S. Pat. No. 3,077,742(Brown) which discloses a manually operated system fixed to piers.

A significant concern of a boat owner with a waterfront residence is theissue of convenient access to their boat. The simplest form of wharf ordock is a fixed deck or platform supported above the water by piers.U.S. Pat. No. 3,081,601 (Fentiman), U.S. Pat. No. 3,999,397 (Albery) andU.S. Pat. No. 4,968,182 (Westiwell) all disclose fixed platformssupported above the water by piers which may be suitable for waterfrontresidences. However fixed docking platforms are inconvenient whenboarding or disembarking from the boat because the boat will rarely beat the same level as the platform because of the effect of tides.

This difficulty is overcome by the floating dock. Prior art floatingdocks which may be suitable for waterfront residences are illustrated byU.S. Pat. No. 4,287,625 (Dawson), U.S. Pat. No. 4,581,784 (Rousseau etal.), U.S. Pat. No. 4,938,629 (Boudrias) and U.S. Pat. No. 5,165,823(Cupples).

Both floating docks and boat lifts are advantageous to the boat ownerwith a waterfront residence, however such residences generally have onlylimited water space to accommodate both structures and it would beconvenient if they could be combined. Such a combination would providespace-saving, functional, aesthetic and cost benefits.

A known solution is to mount a boat lift on a floating structure. U.S.Pat. No. 3,265,024 (Kramlich), U.S. Pat. No. 3,777,691 (Beale), U.S.Pat. No. 5,099,778 (Palen), U.S. Pat. No. 5,655,850 (Holmgren), and U.S.Pat. No. 5,664,513 (Echelbarger), all disclose free floating pontoondocks having boat lift mechanisms which may be suitable for use withrecreational boats

However a known problem with floating boat lifts is that they have poorstability when the boat is raised above water because of the high centreof gravity in that position. The entire system may roll or pitch withinthe water, especially in rough conditions, carrying with it thepotential of the boat sliding from its resting position into the water,and either damaging or sinking the boat. Furthermore floating dockssuffer from the same maintenance issues as boats and it would beadvantageous if it could be treated in the same way by removing it fromthe water between uses or in adverse conditions.

Another known solution is a vertically movable platform which can beraised or lowered to lift the vessel clear of the water. U.S. Pat. No.3,276,211 (Drake) discloses a floating platform with piers that may beraised or lowered to contact the sea floor and where the platform can beraised above the water on the piles. The platform has centrally locatedsection that may be displaced relative to the surrounding platform by amechanical linkage and may be submerged to accept a boat for lifting.The platform can only be raised above the water in a two step processwhere the main section is lifted by the linkage against the buoyancy ofthe central section, the main section is locked to the piles and thecentral section lifted by the linkage up the main section. Because ofthis action the platform cannot be raised above the water while carryinga boat.

U.S. Pat. No. 2,942,425 (De Long et al.) and U.S. Pat. No. 2,775,869(Pointer) each also disclose a floating platform with piers that may beraised or lowered to contact the sea floor and where the platform can beraised above the water on the piles. The platform may also be submergedbeneath the water so that a boat can be maneuvered above it so that whenthe platform is again raised the boat is lifted by it above the surfaceof the water. However to perform the lifting operation the deck of theplatform must be completely submerged and the boat access and dockfunctionality of the platform are lost. While U.S. Pat. No. 2,942,425discloses a dual platform, one of the platforms must always be above theother and therefore the upper platform cannot function as an access deckor dock to the boat that is being lifted by the lower platform.

None of the identified prior art documents disclose a system in whichthe mechanism which lifts the boat on piers also lifts a floatingplatform but in which the boat lifter and the platform are otherwiseindependent of each other, and in which the lifted platform still servesas a dock and provides access to the lifted boat.

OBJECTS

A principal object of the invention is the provision of improved boatlifts of the cradle type that are associated with some form of permanentberth.

The docking system of the present invention allows a floating dock and aboat to be raised out of the water in a stowed position, clear of anywave action, and lowered into the water when required. A walkwayprovides access to the dock at all times. When in the raised (stowed)position, the dock assumes the functionality of a pier. When in thelowered position, the dock and boat are floating and allow easy accessto the boat from the floating dock. The floating dock lift is a solutionthat will suit many water front owners who currently believe that a pierand boat solution is not practical.

Other objects and further scope of applicability of the presentinvention will become apparent from the detailed description givenhereinafter; it should be understood, however, that that detaileddescription, while indicating preferred embodiments of the invention, isgiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

SUMMARY OF THE INVENTION

The objects are accomplished, in part, in accordance with the inventionby the provision of a docking system for lifting a vessel above thesurface of a body of water comprising:

-   -   a plurality of piles fixed to the bed of the body of water;        a platform located, and retained, between at least some of the        piles and floating on, and having an upper surface located above        the surface of, the body of water;    -   frame means located between and supported on, the piles and        capable of being raised above and lowered below the surface of        the body of water and capable of supporting the vessel above the        surface of the body of water; and,    -   the frame and the platform being relatively disposed such that        when the frame means lifts the vessel above the surface of the        body of water it also lifts the platform above the surface of        the body of water.

Accordingly, it is a principal object of the invention to provide afloating dry dock that can be easily adjusted for use with a largeselection of different size boats and boat lifts.

It is another object of the invention to provide a floating dry dockthat is attractive as well as structurally sound.

It is a further object of the invention to provide a floating dry dockthat can be easily and economically manufactured.

Still another object of the invention is to provide a floating dry dockthat is easily moved from one location to the next.

These and other objects of the present invention will become readilyapparent upon further review of the following specification anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the invention may be had by referenceto the accompanying drawings in which:

FIG. 1 is a plan view of a docking system according to the presentinvention.

FIG. 2 is an elevation view of a docking system according to the presentinvention in a raised position.

FIG. 3 is an elevation view of a docking system according to the presentinvention in a lowered position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring in detail to the drawings, in which identical parts areidentically marked, the docking system of the present inventioncomprises a boat lift having piles 1 (usually four but eight for largerlifts) made of concrete or timber, cable winch motors 2 (typically twofor small lifts and four for larger lifts), lifter beams 3, boat carriersupports 4, floating dock modules 5, and a suspended walkway 6.

-   -   Referring now to the drawings and in particular to FIG. 1, the        piles are driven into the riverbed or ocean floor 7 and extend        above the high water line by a distance of one to two metres.        These are placed at each corner of a rectangle. The length of        the rectangle is determined by adding the width dimension of the        desired boat and the width of the dock plus about one metre to        allow for maneuverability. The width of the rectangle is        determined by the support necessary for the boat and the desired        dimension of the dock. The size and number of piles is        determined by the weight of the boat and floating dock modules.

A cable winch motor is an assembly (not shown) of an electric motor,cable winch and cable in the one housing. Cable winch motors areattached near to, or at the top of, the piles and have sufficientaggregate power to lift the boat and floating dock modules. The size,number and arrangement of the cable winch motors are dependent on theweight to be lifted. Lifter beams are structural beams (usuallymetallic) with sufficient strength to lift the weight of the boat andfloating dock modules. Two beams are placed parallel to each other andare attached, at each end, to the cables hanging down from the cablewinch motors.

Boat carrier supports are attached to the top of, and at right anglesto, the lifter beams so that a boat is supported in its upright positionwhen the boat is out of the water. The framework of the carrier supportsmay, but does not necessarily, conform to the general configuration ofthe hull bottom. Its sole purpose is to support the vessel and,accordingly, there is little limitation to its shape and configuration.It may be entirely rigid or portions may be of flexible sheet or webmaterials.

Floating dock modules are polyethylene or similar lightweight moldingsthat, when connected together and placed in water, form a floatingplatform. One method of holding the dock in position is to anchor thedock to piles by using pile brackets 8. Pile brackets allow the dock torise and fall with the tide.

A suspended walkway provides access from a fixed structure 9 (such asland or jetty) to the floating dock. The suspended walkway is securelyhinged at the fixed structure end while the other end rests on thefloating dock allowing the suspended walkway to raise and lower with thedock.

Referring to FIGS. 2 and 3, when the lifting beams are in the raisedposition (that is, the dock and boat are out of the water) and it isrequired to use the boat, power is applied to the cable winch motors tocause them to unwind the cable thereby lowering the lifter beams, boatand floating dock into the water to a depth that allows the boat tofloat free. The floating dock also floats but is held in position by thepile brackets. When the boat is free, the floating dock can be raised byreversing the cable winch motors thereby raising the lifter beams whichthen raise the floating dock and walkway. When the boat is required backin the stowed position, the lifter beams are lowered back into the waterto allow the boat to be positioned over the boat carrier supports. Poweris then applied to the winch motors to cause them to wind up the cablethereby raising the lifter beams, boat, floating dock and walkway.

It will be appreciated if the foregoing is presented by way ofillustration only, and not by way of any limitation, and that variousalternatives and modifications may be made to the illustrated embodimentwithout departing from the spirit and scope of the invention. It is tobe understood that the present invention is not limited to the soleembodiment described above, but encompasses any and all embodimentswithin the scope of the following claims.

1. A docking system for lifting a vessel above the surface of a body ofwater comprising: a plurality of piles fixed to the bed of the body ofwater; a platform located, and retained, between at least some of thepiles and floating on, and having an upper surface located above thesurface of, the body of water; frame means located between and supportedon, the piles and capable of being raised above and lowered below thesurface of the body of water and capable of supporting the vessel abovethe surface of the body of water; and, the frame and the platform beingrelatively disposed such that when the frame means lifts vessel abovethe surface of the body of water it also lifts the platform above thesurface of the body of water.
 2. The docking system of claim 1 whereinthe platform comprises at least one floating dock module.
 3. The dockingsystem of claim 2 wherein the floating dock modules comprised ofpolyethylene or similar lightweight moldings that, when connectedtogether and placed in water, form a floating platform.
 4. The dockingsystem of claim 3 wherein the floating dock modules are anchored to thepiles by brackets that allow the them to rise and fall with the tide. 5.The docking system of claim 4 further comprising a walkway to provideaccess from a fixed structure such as land or a jetty to the floatingplatform, the walkway being hinged at the fixed structure end while theother end rests on the floating platform allowing the walkway to followthe movement of the platform.
 6. The docking system of claim 1 whereinthe piles are placed in the shape of a rectangle.
 7. The docking systemof claim 6 wherein the width of the rectangle is greater than thecombined width of the vessel to be lifted and the width of the platform.8. The docking system of claim 7 wherein the piles extend above the highwater line of the body of water.
 9. The docking system of claim 1wherein the frame comprises parallel lifter beams and boat carriersupports attached to the top of, and at right angles, to the lifterbeams so that the vessel is supported in its upright position when it islifted out of the water.
 10. The docking system of claim 9 whereinlifter beams are attached at each of their ends to cables wound by cablewinch motors attached near to, or at the top of, the piles.
 11. Thedocking system of claim 10 wherein the cable winch motor is an assemblyof an electric motor, cable winch and cable in the one housing.
 13. Adocking system for lifting a vessel above the surface of a body of watercomprising: a plurality of piles fixed to the bed of the body of water,wherein the piles are placed in the shape of a rectangle, the width ofthe rectangle is greater than the combined width of the vessel to belifted and the width of the platform, and the piles extend above thehigh water line of the body of water; a platform located, and retained,between at least some of the piles and floating on, and having an uppersurface located above the surface of, the body of water, wherein theplatform comprises at least one floating dock module, the floating dockmodules comprised of polyethylene or similar lightweight moldings that,when connected together and placed in water, form a floating platform,and the floating dock modules are anchored to the piles by brackets thatallow the them to rise and fall with the tide; a walkway to provideaccess from a fixed structure such as land or a jetty to the floatingplatform, the walkway being hinged at the fixed structure end while theother end rests on the floating dock allowing the walkway to follow themovement of the platform; frame means located between and supported on,the piles and capable of being raised above and lowered blow the surfaceof the body of water and capable of supporting the vessel above thesurface of the body of water, wherein the frame comprises parallellifter beams and boat carrier supports attached to the top of, and atright angles to, the lifter beams so that the vessel is supported in itsupright position when it is lifted out of the water, the lifter beamsare attached at each of their ends to cables wound by cable winch motorsattached near to, or at the top of, the piles, and the cable winch motoris an assembly of an electric motor, cable winch and cable in the onehousing; and, the frame and the platform being relatively disposed suchthat when the frame means lifts vessel above the surface of the body ofwater it also lifts the platform above the surface of the body of water.